During the propagation of electromagnetic waves in a medium :
1. Electrical energy density is double of the magnetic energy density
2. Electric energy density is half of the magnetic energy density
3. Electrical energy density is equal to the magnetic energy density
4. Both electrical and magnetic energies are equal to zero
Match List-I (Electromagnetic wave type) with List-II (the association/application) and select the correct option from the choices given below the lists :
|
List-I |
|
List-II |
(A) |
Infrared waves |
(i) |
To treat muscular strain |
(B) |
Radio waves |
(ii) |
For broadcasting |
(C) |
X-rays |
(iii) |
To detect fracture of bones |
(D) |
Ultraviolet rays |
(iv) |
Absorbed by the ozone layer of the atmosphere |
(A) (B) (C) (D)
1. (iv) (iii) (ii) (i)
2. (i) (ii) (iv) (iii)
3. (iii) (ii) (i) (iv)
4. (i) (ii) (iii) (iv)
An electromagnetic wave of frequency is propagating along z-axis. The amplitude of electric field is 4 V/m . If , then average energy density of electric field will be:
1.
2.
3.
4.
A lamp emits monochromatic green light uniformly in all directions. The lamp is 3% efficient in converting electrical power to electromagnetic waves and consumes 100 W of power. The amplitude of the electric field associated with the electromagnetic radiation at a distance of 5 m from the lamp will be nearly :
1. 4.02 V/m
2. 2.68 V/m
3. 5.36 V/m
4. 1.34 V/m
If denote microwaves, X-rays, infrared, gamma rays, ultraviolet, radiowaves and visible parts of the electromagnetic spectrum by M,X,I,G,U,R and V the following is the arrangement in ascending order of wavelength:
1. M,R,V,X,U,G and I
2. R,M,I,V,U,X and G
3. G,X,U,V,I,M and R
4. I,M,R,U,V,X and G
Match List-I (wavelength range of electromagnetic spectrum) with List - II (Method of production of these waves ) and select the correct option from the choices given below the lists :
|
List-I |
|
List-II |
(A) |
700 nm to 1 mm |
(i) |
Vibrations of atoms and molecules |
(B) |
1 nm to 400 nm |
(ii) |
Inner shell electrons in atoms moving from one energy level to lower level |
(C) |
<10-3 nm |
(iii) |
Radioactive decay of nucleus |
(D) |
1 mm to 0.1 m |
(iv) |
Magnetron valve |
(A) (B) (C) (D)
1. (iii) (iv) (i) (ii)
2. (i) (ii) (iii) (iv)
3. (ii) (iii) (iv) (i)
4. (iv) (iii) (ii) (i)
For plane electromagnetic waves propagating in the z-direction, which one of the following combination gives the correct possible directions for field respectively ?
1.
2.
3.
4.
Microwave oven acts on the principle of :
1. transferring electrons from lower to higher energy levels in water
2. giving rotational energy to water molecules
3. giving vibrational energy to water molecules
4. giving translational energy to water molecules
Magnetic field in a plane electromagnetic wave is given by
Expression for corresponding electric field will be (where c is speed of light)
1.
2.
3.
4.